IBM Personal Computer XT Manual To Operations page 349

or cursor with its background; for example, changing a
red character on a black background to a black
character on a red background.
RF. Radio frequency.
RF modulator. The device used to convert the
composite video signal to the antenna level input of a
home TV.
ROM. Read-only memory.
ROM/BIOS. The ROM resident basic input/output
system, which provides the level control of the major
I/O devices in the computer system.
run. A single continuous performance of a computer
program or routine.
schematic. The representation, usually in a drawing or
diagram form, of a logical or physical structure.
SDLe. Synchronous Data Link Control.
sector. That part of a track or band on a magnetic
drum, a magnetic disk, or a disk pack that can be
accessed by the magnetic heads in the course of a
predetermined rotational displacement of the particular
device.
setup. (1) In a computer that consists of an assembly
of individual computing units, the arrangement of
interconnections between the units, and the
adjustments needed for the computer to operate. (2)
The preparation of a computing system to perform a
job or job step. Setup is usually performed by an
Glossary-7